The present invention is directed to a vehicle chassis and, more particularly, to a wagon chassis which is capable of being adjusted to a variety of lengths between maximum and minimum.
Chassis are known in the art which generally include cylindrical pipes which are capable of longitudinal adjustment relative to each other to permit adjustment of the chassis length. The pipes have holes positioned at intervals along their length to permit the pipes to be locked in selected adjustment positions. These prior adjustable length chassis typically include front and rear axle assemblies each of which includes an axle beam extending transversely of the chassis on which the vehicle wheels are mounted, and a cylindrical pipe reach beam on each of the axle beams extending forward of the rear axle beam and rearward from the front axle beam. A cylindrical center pipe is slidably received into the respective cylindrical reach beams to permit longitudinal adjustment of the chassis length.
These prior adjustable length chassis suffer several disadvantages. One disadvantage is that the number of length adjustments is limited to the number of adjustment holes provided and the positioning of those holes. Thus, exact fractional adjustment is not possible. Another disadvantage is that the minimum length of adjustment of the chassis is limited to the total combined length of the reach beam pipes which are typically of identical diameter. When these prior chassis are adjusted to their minimum length, that length is reached when the ends of the reach beams abut each other. Thus, not only is adjustment to minimum length limited, but the total range of adjustment between the maximum and minimum lengths is also limited.
The adjustable length vehicle chassis of the present invention overcomes these several disadvantages. In the chassis of the present invention length adjustment may be accomplished over an essentially infinite number of adjustment lengths without restriction to only a few selected lengths, and the adjustment may be to a fraction of an inch. The chassis of the present invention is also capable of adjustment to a maximum length which is substantially greater than the maximum lengths possible in the prior known adjustable chassis. Moreover, the total range of adjustment between the maximum and minimum lengths in the chassis of the present invention is substantially greater than the ranges attained by the prior adjustable chassis. In addition to the foregoing advantages, the adjustable length vehicle chassis of the present invention permits torsional twisting which is desirable where the chassis is to operate on uneven terrain.
In one principal aspect of the present invention, a vehicle chassis which is adjustable between maximum and minimum lengths includes first and second axle assemblies each having first and second axle beams, respectively, extending transversely of the chassis and adapted to have wheels mounted thereon. First and second reach beams are mounted on the first and second axle beams, respectively, and extend longitudinally from and substantially perpendicular to the respective axle beams and toward each other. Each of the reach beams terminate in distal ends opposite their respective axle beams. A center beam is also provided having opposite distal ends. The first and second reach beams and the center beam are dimensioned relative to each other to telescopically interfit with each other such that the distal ends of the center beam are positioned adjacent the first and second axle beams and the distal end of at least one of the reach beams is positioned adjacent to the axle beam of the other reach beam when the chassis is at its minimum length. Locking means locks the beams relative to each other when the chassis is at its minimum length.
In still another principal aspect of the present invention, when the aforementioned chassis is at its minimum length, the center beam is positioned within both of the reach beams and one of the reach beams is positioned in the other reach beam.
In still another principal aspect of the present invention, the aforementioned first reach beam comprises side walls spaced from each other by a top wall, and the top wall comprises a slot extending over a substantial part of its longitudinal length to permit fractional adjustment of the length of the chassis.
In still another principal aspect of the present invention, the aforementioned first reach beam is a hat channel in cross section, the second reach beam is a U-shaped channel in cross section and the center beam is a box channel in cross section having a slot in one side thereof.
In still another principal aspect of the present invention, the aforementioned locking means includes a plate overlying the aforementioned slot, and vertically extending first fastener means mounted adjacent one distal end of the center beam and extending upwardly through the slot and plate and removably fastened to the plate.
In still another principal aspect of the present invention, the aforementioned fastening means also includes vertically extending second fastener means mounted adjacent the other distal end of the center beam, and openings in the second reach beam at least adjacent the second axle beam. The second fastener means extends upwardly through the openings and are removably fastened to the second reach beam.
In still another principal aspect of the present invention, the aforementioned second reach beam also includes at least one opening adjacent its distal end and the second fastener means extends upwardly through the last mentioned opening and are removably fastened to the second reach beam when the chassis is at its maximum length.
These and other objects, features and advantages of the present invention will be more clearly understood upon consideration of the detailed description of the preferred embodiment of the invention which will be described to follow.